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Z. Tsvetanov, W. Zheng (JHU), SDSS Collaboration
We report the discovery of a quasar at redshift z=5.28 selected from the Sloan Digital Sky Survey (SDSS) comissioning data.
Quasar selections at z > 5 suffer increasing contamination from cool stars and unresolved z ~1 galaxies. To fight this severe pollution problem we are carrying out a project to obtain the infrared magnitudes for selected SDSS targets. The infrared photometry enable us to isolate a handful of highly potential targets out of a an initial list of several hundreds. The IR imaging was obtained at the NASA IRTF on Mauna Kea, Hawaii and the follouw-up optical (0.6--1 \mu) spectra were taken with the 3.5m telescope at the Apache Point Observatory, New Mexico. Two quasars at z = 4.7 and 5.28 were found from just five candidates. The z = 5.28 quasar is the highest redshift known to date for luminous quasars, and its prominent emission lines provide insight into the cosmic evolution in the early universe. The new discovery shows the power of SDSS, as well as the effectiveness of the SDSS/IR selection.
The SDSS is a joint project of the University of Chicago, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, Max-Planck-Institute for Astronomy, Princeton University, United States Naval Observatory and the University of Washington. Funding has been provided by the Alfred P. Sloan Foundation, the member institutions, NASA, NSF, the U.S. DoE, and the Ministry of Education of Japan.
The author(s) of this abstract have provided an email address for comments about the abstract: zlatan@pha.jhu.edu